Many sources now indicate that the incidence of heroin abuse has been increasing steadily over the past few years, partly due to the fact that the purity of street heroin has increased nearly tenfold while prices have consequently decreased. With increased purity and cheaper heroin has also come a kind of societal amnesia about the dangers of heroin use, particularly now that high purity heroin allows the drug to be used intranasally very effectively by individuals who wish to get a heroin effect. As a result, heroin dependence (addiction) has also been increasing, particularly among young people and users who do not inject. The increase in heroin addiction has created a renewed need to improve methods for opiate detoxification. Although many methods have been proposed to make opiate detoxification less painful and therefore more readily acceptable to opiate dependent patients, all the methods are problematic. Detoxification with a taper of methadone or other opioids usually results in a mild but protracted withdrawal syndrome following detoxification, during which relapse risk is very high. Precipitated withdrawal procedures using the opiate antagonist medication , naltrexone, have had favorable reports in the literature, but they have not met with widespread clinical acceptance, probably in part because they are not acceptable to many patients. Recent modifications of these precipitated procedures involve general anesthesia, but these newer techniques may not be sufficiently safe or cost-effective in the long run to justify their use. The proposed research involves a double-blind comparison of two detoxification procedures, the first is the classical clonidine-naltrexone precipitated withdrawal detoxification, developed by Dr. Herbert Kleber and others. The second is a procedure using buprenorphine, a partial mu opiate agonist medication, which has been promisisng in open trials as a potential detoxification agent. Here, buprenorphine will be used as a transitional medication prior to induction onto naltrexone maintenance. The specific aim of this study is to test the following hypothesis: Detoxification using buprenorphine as transitional medication from heroin or methadone to naltrexone will be superior to naltrexone precipitated detoxification on both subjective and objective measures of opioid withdrawal, thus increasing detoxification completion rates for the buprenorphine to naltrexone group, compared with the naltrexone only group.